Isocyanates, especially 2-Methyl-acrylic acid 2-isocyanato-ethyl ester (MOI), are versatile organic compounds and many different routes for their production are known:                via phosgenation of 2-(2-Methyl-acryloyloxy)-ethyl-ammonium 4-Chlorophenyl-sulfonates as described in DE 1929581,        via phosgenation of 2-(2-Methyl-acryloyloxy)-ethyl-ammonium; chloride as described in U.S. Pat. No. 2,821,544,        via phosgenation of isopropenyl-oxazolidin as described in EP 0 000 144,        via phosgenation of oxazolinidone as describe in JP 1990-145555,        via cleavage of an urethane using PCl5 as described in U.S. Pat. No. 2,718,516,        via cleavage of an urethane using chlorosilane as described in EP 0 849 258,        via cleavage of an urethane using boron chloride as described in U.S. Pat. No. 5,457,229 or        via dehydrohalogenation as described in WO 2005/092842.        
However, most of the processes described above require the use of phosgene, which is often not desirable. Phosgene is a highly reactive gas and considered to be toxic.
Moreover, the isocyanates which are obtained by using phosgene typically contain a considerable high amount of chloride, which is often not desirable. Moreover, other undesirable contaminations like phosphorus- or silane-compounds or saturated isocyanate esters are sometimes found. These undesired contaminations are sometimes difficult to remove, too.
JP 1990-129163 relates to a process which comprises the step of reacting an imidazole derivative with carbonyl chloride, reacting the resultant compound with a monoalkanolamine, and then esterifying the resultant compound using an unsaturated carboxylic acid or its chloride or ester to give an isocyanatoalkyl ester of an unsaturated carboxylic acid. According to this process the resultant compounds typically contain a large amount of by-products, which may derive from the unsaturated group (e.g., HCl adduct of the unsaturated group). This may cause disadvantages like low reaction yield and the need for further purification.
In order to lower the content of chloride a couple of additional processes are known:                using tertiary amines as described in WO 2005/092842,        using amines and epoxides as described in WO 2005/012237,        using imidazoles as described in JP 05058982,        by distillation in presence of epoxies as described in EP 0 936 214.        
The above processes, however, are sometimes complicated, require additional efforts and suffer from yield losses.